Port Type CPI-C: Maintaining Port Definition


Some of the parameters must be configured in accordance with the R/2 System communication system (“DC system”) (CICS, IMS under MVS/VSE or UTM under BS2000). Examples of these are provided below:

Choose SAP Menu ® Tools ® IDOc Interface/ALE ® Administration ® Runtime Settings ® Maintain Port (WE21).


       1.      Position the cursor on CPI-C and choose .

       2.      Enter a name and define the port. Configure the following CPI-C parameters:

·         RFC destination (for example K50 Test) with the logon data for the R/2 System

·         Host destination

TXCOM entry with the technical communications data (for example K50).

·         Buffer size

Length of the CPI-C data buffer (in bytes) which is transmitted with a SEND or RECEIVE command. The maximum value is 8191 bytes.

·         Number buffer

Number of SEND commands transmitted before a RECEIVE command is sent, according to the IDoc CPI-C protocol. A SEND command corresponds to one buffer.

·         Character string in the R/2 System. This entry is essential to ensure that the data stream is converted correctly.

·         Transmission modes in accordance with the CPI-C protocol. See the examples provided below. The exact meaning of the following parameters is explained in the R/2 manual, S53.2 (description of the CPI-C Interface):

-         Synchronous transmission mode

If you choose synchronous transmission mode, the Number buffers parameter is no longer evaluated.

-         Send acknowledgment of receipt

The R/2 System must send a confirmation after data transfer. This confirmation does not correspond to a status confirmation, therefore also no new status.

-         Connection terminated by R/2

       3.      Define an additional option for status confirmation (status report) for the R/2 System:

Specify whether the status records are to be sent to the R/2 System immediately when an IDoc is received, later (that is, scheduled using a report), or not at all.


The transmission parameters are now set. You must still schedule reports for IDoc inbound processing and for subsequent status confirmations for the R/2 System. See Port Type CPI-C (Inbound Processing): Scheduling Reports


CICS data communication system (MVS/VSE operating system)

The selected CPI-C data buffer should be as large as possible (at least 4 KB). The product of the buffer size and the number of buffers must be significantly less than the 32 KB CICS dialog buffer. Therefore a number buffer between 3 and 6 is used (Example: 4 KB ґ 6 = 24 KB).

For performance reasons, you should not activate the synchronous transmission mode.

IMS data communication system (MVS/VSE operating system)

Depending on the size of the IMS message queue, the length of the CPI-C data buffer should not exceed 1 - 1.5 KB.

Always activate the following transmission options under IMS:

·        Synchronous transmission mode

·        Send acknowledgment of receipt

·        Connection terminated by R/2

UTM data communication system (BS2000 operating system)

The CPI-C data buffer size should be between approximately 5 KB and the maximum value (8191 bytes). There are no constraints concerning the size of the dialog buffer.